alibaba/Sentinel · error · IllegalArgumentException

Invalid second interval (cannot divide by 60):

Error message

Invalid second interval (cannot divide by 60): 

What it means

This is the first divisibility rule in validateInterval: for intervals of 1-59 seconds, EagleEye requires that intervalSeconds evenly divides 60 (60 % intervalSeconds == 0) so flush boundaries align with minute boundaries in the time-based file naming/rolling scheme. Values like 7, 8, or 45 throw IllegalArgumentException.

Source

Thrown at sentinel-core/src/main/java/com/alibaba/csp/sentinel/eagleeye/StatLoggerBuilder.java:100

            EagleEyeRollingFileAppender rfAppender = new EagleEyeRollingFileAppender(filePath, maxFileSize);
            appender = new SyncAppender(rfAppender);
        }

        EagleEyeLogDaemon.watch(appender);
        return new StatLogger(loggerName, appender, intervalMillis, maxEntryCount,
            entryDelimiter, keyDelimiter, valueDelimiter);
    }

    public StatLogger buildSingleton() {
        return StatLogController.createLoggerIfNotExists(this);
    }

    static void validateInterval(final long intervalSeconds) throws IllegalArgumentException {
        if (intervalSeconds < 1) {
            throw new IllegalArgumentException("Interval cannot be less than 1" + intervalSeconds);
        } else if (intervalSeconds < 60) {
            if (60 % intervalSeconds != 0) {
                throw new IllegalArgumentException("Invalid second interval (cannot divide by 60): " + intervalSeconds);
            }
        } else if (intervalSeconds <= 5 * 60) {
            if (intervalSeconds % 60 != 0) {
                throw new IllegalArgumentException("Invalid second interval (cannot divide by 60): " + intervalSeconds);
            }
            if (60 % intervalSeconds != 0) {
                throw new IllegalArgumentException("Invalid second interval (cannot divide by 60): " + intervalSeconds);
            }
        } else if (intervalSeconds > 5 * 60) {
            throw new IllegalArgumentException("Interval should be less than 5 min: " + intervalSeconds);
        }
    }
}

View on GitHub (pinned to a3f40ba8e9)

Solutions

1. Use a divisor of 60: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, or 30 seconds.
2. Round computed intervals to the nearest valid divisor before calling the builder.
3. Validate candidate intervals at startup with a helper mirroring the divisibility rule.

Example fix

// before
builder.intervalSeconds(7); // 60 % 7 != 0 -> throws

// after
builder.intervalSeconds(5); // 60 % 5 == 0

boolean isValidSubMinute(int s) { return s >= 1 && s < 60 && 60 % s == 0; }
if (!isValidSubMinute(intervalSeconds)) { /* pick 1,2,3,5,10,15,30 */ }

When it happens

Trigger: Calling intervalSeconds(n) with 1 <= n < 60 and 60 % n != 0 — e.g. 7s, 8s, 9s, 11s, 45s. Commonly a computed interval (60/7 rounded) or a copied example value that is not a divisor of 60.

Common situations: Teams pick a 'nice' number like 15 or 30 (valid) vs 20 (valid) but also 7 or 45 (invalid) without knowing the constraint. Interval derived from another setting (e.g. one tenth of a 7-second upstream cycle). Config values copied between projects with different validation rules.

Related errors

• Interval should be less than 5 min:
• Max entry count should be at least 1:
• Interval cannot be less than 1
• keys empty or null: ${keys}
• keys empty or null

AI-assisted analysis of alibaba/Sentinel@a3f40ba8e9 (2026-08-14). Data as JSON: /api/errors/b3f4ec3cec66ed20. Report an issue: GitHub.